The biochemistry of tubulin and its interaction with other proteins in various cell processes will be investigated through five different approaches. 1) A 2-dimensional polyacrylamide gel system will be developed to separate various organelll-specific tubulins according to isoelectric point and relative hydrophobicity, permitting analysis of specific tubulin pools during cell division and early development. 2) Premitotic and preciliogenesis tubulin in inactive, particulate forms will be isolated and purified in order to determine whether post-translational modification or complex-formation with other proteins are involved in mobilizing or maintaining these apparent storage forms. 3) A minor ciliary structural protein, synthesized de novo and quantally during ciliary elongation, will be characterized and the possible synthesis of the same of similar proteins will be investigated during mitotic apparatus assembly. 4) Cytoplasmic dynein from sea urchin eggs will be purified and characterized. Its binding to microtubules in vitro and its presence in the mitotic apparatus and brain will also be explored. 5) The association of ciliary membrane tubulin or flagellar membrane glycoprotein within the membranes will be studied through chemical crosslinking reagents and freeze-fracture/freeze-etch techniques. The flagellar membrane glycoprotein will be characterized and calcium-dependent ATPases identified in ciliary and flagellar membranes.